Description: All models. 8.1l. All models. 4.3l. S-series. 4.3l. Astro, Safari. 4.3l. 6 cylinder. Code Yfky Yfpz Yfyy. 5.3L. 5.7L. GTO. This part requires programming and/or special setup procedures GM Service Information describes the procedures and special tools needed to ensure proper operation in the vehicle Dictates the operation of your vehicle's vital systems, which is critical to the performance of your vehicle

Description: 8 cylinder. 5.3 & 6.0L. 6 cylinder. 8.1l. 2003-07. This GM Genuine Part is designed, engineered, and tested to rigorous standards and is backed by General Motors Original equipment parts are designed to work with your GM vehicle safety systems - aftermarket replacement parts may not meet the same OE safety regulations, depending on the part type